Membrane process for separating a mixture containing dewaxed oil and dewaxing solvent

Abstract

A charge containing dewaxed oil/dewaxing solvent may be treated to effect separation of components by a thermally cross-linked hydrocarbon-derived elastomer membrane, typified by polybutadiene.

What is claimed: 
     
       1. The process for treating a charge containing dewaxing solvent and dewaxed oil which comprises passing said charge containing dewaxing solvent and dewaxed oil into contact with, as separating membrane, a non-porous elastomer separating membrane layer of a non crystalline, carbon-carbon backbone polymer of molecular weight M n  of 1000-100,000;   maintaining the pressure on the low pressure discharge side of said membrane above the vapor pressure of said permeate thereby maintaining said permeate in liquid phase;   maintaining the pressure on the high pressure retentate side of said membrane above the vapor pressure of said charge containing dewaxing solvent and dewaxed oil and sufficient to drive permeate through said membrane thereby maintaining said charge containing dewaxing solvent and dewaxed oil and said retentate in liquid phase;   recovering said permeate containing increased content of dewaxing solvent and decreased content of dewaxed oil; and   recovering said retentate containing increased content of dewaxed oil and decreased content of dewaxing solvent.   
     
     
       2. The process for treating a charge containing dewaxing solvent and dewaxed oil as claimed in claim 1 wherein said separating membrane is a polymer of a butadiene of molecular weight M n  of 1000-100,000. 
     
     
       3. The process for treating a charge containing dewaxing solvent and dewaxed oil as claimed in claim 1 wherein said separating membrane is a polymer of 1,3-butadiene of molecular weight M n  of about 2800. 
     
     
       4. The process for treating a charge containing dewaxing solvent and dewaxed oil as claimed in claim 1 wherein said separating membrane has been thermally cross-linked. 
     
     
       5. The process for treating a charge containing dewaxing solvent and dewaxed oil as claimed in claim 1 wherein said separating membrane has been thermally cross-linked at 125°-170° C. 
     
     
       6. The process for treating a charge containing dewaxing solvent and dewaxed oil as claimed in claim 1 wherein said separating membrane is thermally and chemically cross-linked with a radical initiator. 
     
     
       7. The process for treating a charge containing dewaxing solvent and dewaxed oil as claimed in claim 1 wherein said separating membrane is selected from the group consisting of homopolymer and copolymer elastomers of mono-olefins and dienes. 
     
     
       8. The process for treating a charge containing dewaxing solvent and dewaxed oil which comprises passing said charge containing dewaxing solvent and dewaxed oil into contact with, as separating membrane, a non-porous elastomer separating membrane layer of a non crystalline, carbon-carbon backbone polymer of 1,3-butadiene of molecular weight M n  of about 2800;   maintaining the pressure on the low pressure discharge side of said membrane above the vapor pressure of said permeate thereby maintaining said permeate in liquid phase;   maintaining the pressure on the high pressure retentate side of said membrane above the vapor pressure of said charge containing dewaxing solvent and dewaxed oil and sufficient to drive permeate across said membrane thereby maintaining said charge dewaxing solvent and dewaxed oil and said retentate in liquid phase;   recovering said permeate containing increased content of dewaxing solvent and decreased content of dewaxed oil; and   recovering said retentate containing increased content of dewaxed oil and decreased content of dewaxing solvent.